ISA ARBORIST STUDY GUIDE QUESTIONS AND ANSWERS 2025
Bark, phloem, cambium, xylem - (ANSWER)When cutting through a tree with a chain saw or drilling into
a tree, you would pass through (in order)
Growth may be stimulated in lateral buds - (ANSWER)If the terminal bud is removed in pruning:
The growth rings of a tree: - (ANSWER)Visible because of the rapid growth rate of earlywood relative to
latewood, can be counted on to approximate trees age, can give information about growth conditions in
previous years.
Cambium - (ANSWER)layer of cells is responsible for outward growth and increased girth of tree.
Mycorrhizae are: - (ANSWER)A symbiotic relationship between fungi and roots.
Douglas-fir (Pseudotsuga menziesii) differs from balsam fir (Abies balsamea) in that: - (ANSWER)They are
not in the same genus.
Opposite leaf arrangement is: - (ANSWER)When two leaves and/or buds are located at the same node
on a twig.
Quercus rubra - (ANSWER)Scientific name of Red Oak.
Quercus (Oak) - (ANSWER)This genus of tree usually does not have an opposite leaf arrangement.
Pines - (ANSWER)These conifers have needles in bundles.
Available oxygen and water - (ANSWER)The primary factor in controlling the depth, spread, and
distribution of tree roots in the soil is/are:
The most fibrous and absorptive portion of a tree's root system is found in? - (ANSWER)Are in the upper
6 inches of soil.
, ISA ARBORIST STUDY GUIDE QUESTIONS AND ANSWERS 2025
Water will drain very slowly out of the planting hole. - (ANSWER)If a planting hole in a clay soil site is
backfilled with sandy soil.
When soil is compacted: - (ANSWER)Total pore space and the percentage of macropores are reduced.
A characteristic of sandy soils in arid regions is: - (ANSWER)They tend to become alkaline, and salts build
up due to the lack of heavy rainfall.
When irrigating trees: - (ANSWER)Infrequent, deep soakings are preferable to frequent, shallow
waterings.
Sandy soils: - (ANSWER)Have a higher infiltration rate than clay soils.
A soil is at field capacity when: - (ANSWER)Gravitational water has drained away.
With sprinkler irrigation: - (ANSWER)Less frequent waterings of longer duration will reduce the
likelihood of salt buildup, water hitting the soil surface can lead to crusting, application rates that
exceed absorption can lead to runoff.
In sites where poor drainage can be a problem, which of the following WILL NOT help ensure plant
survival? - (ANSWER)Placing gravel in the bottom of the planting hole and backfilling with a sandy soil.
8 pounds of nitrogen - (ANSWER)80 pound bag of 10-6-4 fertilizer contains how many pounds of actual
nitrogen?
Nitrogen, phosphorus, potassium - (ANSWER)A complete fertilizer contains?
A tree may not respond immediately to a fertilizer application if: - (ANSWER)A slow release fertilizer was
applied, inadequate soil moisture, and a tree is suffering from collar rot
Bark, phloem, cambium, xylem - (ANSWER)When cutting through a tree with a chain saw or drilling into
a tree, you would pass through (in order)
Growth may be stimulated in lateral buds - (ANSWER)If the terminal bud is removed in pruning:
The growth rings of a tree: - (ANSWER)Visible because of the rapid growth rate of earlywood relative to
latewood, can be counted on to approximate trees age, can give information about growth conditions in
previous years.
Cambium - (ANSWER)layer of cells is responsible for outward growth and increased girth of tree.
Mycorrhizae are: - (ANSWER)A symbiotic relationship between fungi and roots.
Douglas-fir (Pseudotsuga menziesii) differs from balsam fir (Abies balsamea) in that: - (ANSWER)They are
not in the same genus.
Opposite leaf arrangement is: - (ANSWER)When two leaves and/or buds are located at the same node
on a twig.
Quercus rubra - (ANSWER)Scientific name of Red Oak.
Quercus (Oak) - (ANSWER)This genus of tree usually does not have an opposite leaf arrangement.
Pines - (ANSWER)These conifers have needles in bundles.
Available oxygen and water - (ANSWER)The primary factor in controlling the depth, spread, and
distribution of tree roots in the soil is/are:
The most fibrous and absorptive portion of a tree's root system is found in? - (ANSWER)Are in the upper
6 inches of soil.
, ISA ARBORIST STUDY GUIDE QUESTIONS AND ANSWERS 2025
Water will drain very slowly out of the planting hole. - (ANSWER)If a planting hole in a clay soil site is
backfilled with sandy soil.
When soil is compacted: - (ANSWER)Total pore space and the percentage of macropores are reduced.
A characteristic of sandy soils in arid regions is: - (ANSWER)They tend to become alkaline, and salts build
up due to the lack of heavy rainfall.
When irrigating trees: - (ANSWER)Infrequent, deep soakings are preferable to frequent, shallow
waterings.
Sandy soils: - (ANSWER)Have a higher infiltration rate than clay soils.
A soil is at field capacity when: - (ANSWER)Gravitational water has drained away.
With sprinkler irrigation: - (ANSWER)Less frequent waterings of longer duration will reduce the
likelihood of salt buildup, water hitting the soil surface can lead to crusting, application rates that
exceed absorption can lead to runoff.
In sites where poor drainage can be a problem, which of the following WILL NOT help ensure plant
survival? - (ANSWER)Placing gravel in the bottom of the planting hole and backfilling with a sandy soil.
8 pounds of nitrogen - (ANSWER)80 pound bag of 10-6-4 fertilizer contains how many pounds of actual
nitrogen?
Nitrogen, phosphorus, potassium - (ANSWER)A complete fertilizer contains?
A tree may not respond immediately to a fertilizer application if: - (ANSWER)A slow release fertilizer was
applied, inadequate soil moisture, and a tree is suffering from collar rot
